The present invention is directed to a device for detecting the presence of a pulse generator plate associated with a vehicle crankshaft. More particularly, the present invention is directed to a device for detecting whether such a pulse generator plate is missing or defective.
A pulse generator plate may be coupled to a vehicle crankshaft for the purpose of timing the vehicle's engine. The design of such a pulse generator plate may vary. One known embodiment generally comprises a circular plate having a number of circumferentially spaced projections extending therefrom. A pulse generator plate is typically hidden behind a timing chain/belt cover and, therefore, is not readily visible or accessible on an assembled engine.
A sensor is normally also mounted near the pulse generator plate, and is also typically enclosed within the timing chain/belt cover. The sensor produces a magnetic field that extends to at least a portion of the pulse generator plate. The magnetic field is interrupted during engine operation each time one of the extending projections of the pulse generator plate passes therethrough. The interruptions produced by the extending projections induce a current in the sensor, which can be transmitted from the sensor via wire leads that extend through the timing chain/belt cover. As would be understood by one of skill in the art, the currents induced in the sensor can be used in the timing of a vehicle engine.
It occasionally happens that a pulse generator plate is inadvertently not installed to an engine. It also occasionally happens that one or more of the circumferentially spaced projections extending from the pulse generator plate may be broken or missing. Such conditions may be the source of, or contribute to, engine timing problems.
Unfortunately, once an engine has been assembled, it is difficult to ascertain whether one of these conditions exist without first removing the timing chain/belt cover. This can be a time-consuming process that also may first require the removal of various other engine parts. Consequently, it is desired to be able to determine whether a pulse generator plate is missing or damaged without necessitating removal of the timing chain/cover. A device and method of the present invention enables such a determination to be made.